At the moment I have a linear pattern. Essentially my main character starts in an okay state, things go very well, then very badly. That's the first section. The second section is all about her recovery process. The third and final section is when it all comes together and stuff gets resolved, and hopefully she ends up in a better place then where she started (I haven't written the ending yet).
Section 1 is emotional, Section 2 has more laughs. I'm not sure that the two are going to sit very well together, that an innocent unsuspecting reader won't feel there's a sudden gear change. What I'm toying with is having Section 1 run alongside Section 2, swapping from past to present.
Hooray for index cards! I've written out two sets of index cards out with one scene per card and laid them out on the bed (you could use a floor or a large table, I like to work in bed). On the left side of the bedspread is the linear form - Section 1 followed by Section 2. On the right hand side of the bedspread is the past/present form - Section 1 alternating with Section 2.
I can see immediately that each version has pros and cons. For example, the alternating form on the right would mean I could ditch some rather boring linking scenes from Section 1. In fact, I could ditch a mini-subplot that I'm not convinced works. This would be good. On the other hand, there's a BIG moment at the end of Section 1 and a BIG moment at the end of Section 2. Now they're plonked bang smack next to each other. This is bad.
Going back to the left hand side of the bedspread, I can see that the BIG moments are spread out. This is good. However, there is still that major disconnect between the sections that led me to try the alternative form in the first place. This is bad.
It will take a lot of staring at the cards before I make a decision, but think about how much easier it is for me because I can see the novel in both forms easily in front of me. There's no doubt about it; index cards are a very useful addition to any writer's toolbox.